Explore Our Results

A trio of scenarios (‘Conservative’, ‘Mid-range’, and ‘Optimistic’) assess the likely impact of currently enacted federal policies, including the combined impact of two landmark laws passed by the 117th Congress: H.R. 5376, the Inflation Reduction Act of 2022 (IRA) and H.R. 3684, the Infrastructure Investment and Jobs Act of 2021 (IIJA). The three scenarios reflect uncertainty about the effectiveness of IRA provisions and the potential impacts of constraints on supply chains and other rate-limiting factors. See our complete list of policies in IRA and IIJA and assumptions and treatment of each policy under the three Current Policies scenarios. Note: Current Policies scenarios do not currently include the impacts of EPA light duty vehicle tailpipe emissions standards through MY2026 finalized in December 2021 or the heavy-duty vehicle air pollution rule for MY2027 and beyond finalized in December 2022. However, modeled results are very close to compliant with these rules in all cases. Both rules will be explicitly treated in subsequent REPEAT Project analysis.

This scenario reflects the impact of the Infrastructure Investment and Jobs Act of 2021 (H.R. 3684) alone. This scenario removes all Inflation Reduction Act policies from the Current Policies scenario above to isolate the impact of IIJA.

This scenario captures the range of existing policies as of the start of the 117th Congress and inauguration of President Biden in January 2021 and helps set a benchmark against which the impacts of recently enacted or proposed policies can be measured.

This scenario reflects a cost-optimized pathway to reduce economy-wide U.S. greenhouse gas emissions 51% below 2005 levels by 2030 and to net-zero by 2050, consistent with U.S. mid-term and long-term climate goals under the U.N. Framework Convention on Climate Change. It is one of many possible paths to net-zero but serves as an illustrative benchmark to assess whether or not the United States is on track to reach climate mitigation goals.